I know that in E. coli the lactose operon is shut down by CAP protein when binding cAMP. Is this true also for Gram positive bacteria?
I know it's stupid but I answer my own question, for those who are interested. It is different. CAP protein regulates lactose operon only in Gram -. In Gram + the presence of glucose shuts down the operon with another mechanism: the TCRS that relies to concentration of fructose 1,6 phosphate.